// extends 继承

class Person {
  constructor(name) {
    this.name = name;
  }

  say() {
    console.log(`hi, my name is ${this.name}`);
  }
}

class Student extends Person {
  constructor(name, number) {
    super(name); // 父类构造函数
    this.number = number;
  }

  hello() {
    super.say(); // 调用父类成员
    console.log(`my school number is ${this.number}`);
  }
}

const s = new Student('jack', '100');
s.hello();
